The present invention relates to a fixing device and an image forming apparatus such as an electrophotographic printer using the fixing device.
An image forming apparatus includes four image forming units arranged along a transport path of a recording sheet, and a transfer unit is provided so as to face the image forming units via the transport path. The image forming units form developer images of four colors, and the transfer unit transfers the developer images to the recording sheet. A fixing device is provided downstream of the image forming units in a transport direction of the recording sheet. The fixing unit is configured to fix the developer image to the recording sheet.
The fixing device includes a fixing roller, a metal guide, and an endless belt provided around the fixing roller and the metal guide. A heater is provided on a back surface of the belt guide. A pressure roller is pressed against the fixing roller via the endless belt. In an image forming operation, the fixing roller is driven to rotate, and the endless belt and the pressure roller rotate following the rotation of the fixing roller. The endless belt is heated by heat generated by the heater, and is transmitted from the fixing roller via the metal guide. The recording sheet (to which a developer image is transferred) is introduced into between the endless belt and the pressure roller, and the developer image is fixed to the recording sheet by being applied with heat and pressure (see, for example, Japanese Laid-open Patent Publication No. 2011-257455).
In the conventional fixing unit, there are cases where deterioration in image quality may occur.